Fair Ninja will provide the best possible user rating system. Buyers and sellers will be able to rate each other based on their experience.
Isn't it wonderful guys? The sellers who have higher ratings will likely to have more costumers since they have been trusted and proven to be trustworthy so sellers who have a very good experience with them can also refer them to their friends and also buyers having very good trust rate will also be trusted by more sellers.
Because of that rating system, you can identify even the buyers, if they are bogus or not. Or sometimes, there are buyers that are hard to please or having a lot of unreasonable complains. In the case, of second hand items, you should not expect too much because it is not brand new. As long as they are stating the real condition of the said item.
There are second-hand items that are really in good condition. I think Fair Ninja will evaluate which items can seller sell on the platform. The good thing about the platform is that you can reject an item that is not in good condition. And you Smart Contract will not release the payment unless the buyer confirmed that the item is acceptable.